Virus

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Revision as of 18:45, 8 February 2011 by Michael (talk | contribs) (→‎Parvovirus B19: tweak)
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This article collects all things virus. The more general topic of infective thingies is dealt with in microorganisms.

Many virus afflict humans. Only a few of them can be diagnosed histologically.

Viral inclusions - types

Cowdry types:[1]

  • Cowdry type A inclusion:[2]
    • Round eosinophilic material surrounded by a clear halo.
  • Cowdry type B inclusion:[3]
    • Neuropathology thingy. (???)

Images:

Viruses

Herpes simplex virus (HSV)

  • Canker sores - usually HSV-1.
  • Genital herpes - usually HSV-2.

Histology/cytology

Features:[4]

  • Clear "ground glass" nuclei.
    • Rim of peripheral chromatin.
  • Nuclear inclusions.
  • Multinucleation with nuclear molding, i.e. multiple nuclei that touch over a large surface area.

Mnemonic - 3 Ms: Margination, Multinucleation, Molding.

Images:

Cytomegalovirus (CMV)

Microscopic

Features:

  • Very large nucleus (as the name implies) with clearing.
  • Granular cytoplasmic inclusions (red on H&E sections).

Notes:

  • Classically in endothelial cells.
    • In the context of esophageal ulcers, it is therefore useful to biopsy the base of the ulcer - if this is suspected.

Images:

Human papilloma virus

  • Abbreviated HPV.

Microscopic

Features:

  • Koilocytes:
    • Perinuclear clearing.
    • Nuclear changes.
      • Size similar (or larger) to those in the basal layer of the epithelium.
      • Nuclear enlargement should be evident on low power, i.e. 25x. [7]
      • Central location - nucleus should be smack in the middle of the cell.

Images:

See: cervix, esophagus.

Adenovirus

General

Microscopic

Features:

  • "Smudge" cells[5] - black/blue blob ~ 10-15 micrometers. (???)

Notes:

  • May be morphologically similar to CMV, HSV, VZV inclusions.

Images:

Parvovirus B19

General

  • Most significant in pregnant women.
    • Parvovirus attacks the nucleated RBCs of the fetus.

Microscopic

Features:

  • Glassy (red) nuclear inclusions.[7]
  • Nuclear enlargement.

Image:

See also

References